Worldwide marine refrigeration service & in-transit HVAC retrofit

A comprehensive case study of an in-transit overhaul. Our worldwide marine refrigeration service completed an HVAC modernization and R449A refrigerant conversion at sea, saving the shipowner costly dry dock downtime.

Diagnosis and worldwide marine refrigeration service

The main task of our advanced service was the full conversion of outdated systems to modern, low-GWP refrigerants, which is essential under current environmental regulations. The entire assignment on the cargo vessel required flawless logistical planning. Because all stages were executed while the vessel was underway (Riding Squad / In Transit), our worldwide marine refrigeration service had to proceed without disrupting daily operations.

A properly executed “in-transit” retrofit allows shipowners to avoid massive shipyard downtime and commercial delays.

Environmental standards and maritime safety

Phasing out high-GWP refrigerants forces shipowners to adapt their fleets to new legal requirements. Every project executed by our worldwide marine refrigeration service strictly follows environmental guidelines officially set by the International Maritime Organization (IMO). Reducing emissions and improving energy efficiency remain top priorities in modern marine cooling.

Scope of modernization work and system retrofit

Our mobile engineering squad carried out an extensive technical scope across all key cooling circuits:

• Provision plant system: Complete retrofit of circuits #1 and #2. Old Daikin compressors were replaced with new semi-hermetic 4DES-7Y-40S units. We fitted Henry S-5585-CE oil separators, new Danfoss controls, and a dedicated control panel. Danfoss TE2 expansion valves suitable for R449A were installed.
• General air conditioning system: R422D refrigerant was safely recovered. Oil was replaced with synthetic Reniso Triton SEZ 32. The filter-drier housing was upgraded to a replaceable-core model, and the evaporator coil was thoroughly cleaned.
• Control Room AC: Upgraded liquid line with Danfoss GBC12 shut-off valves, DML 164 filters, and SGH 12 sight glasses. A new TE2 expansion valve was fitted.

Final procedures and commissioning measurements

All upgraded systems underwent nitrogen pressure leak testing, followed by deep vacuum evacuation down to 500 microns. Finally, the installations were charged with eco-friendly R449A refrigerant.

Operational measurements confirmed highly stable performance, achieving evaporating temperatures down to -27°C for the provision plant and +5°C for the AC systems. Our worldwide marine refrigeration service delivered another successful in-transit project. Need similar support for your fleet? Check our competencies in system conversions to schedule your retrofit.